The Optical Transport Network (OTN) technology is the core technology for next-generation transport networks. The OTN has strong Tandem Connection Monitoring (TCM) capability, abundant Operation Administration Maintenance (OAM) capability, and out-band Forward Error Correction (FEC) capability, can perform flexible scheduling and management of large-capacity services, and is applicable to backbone transport networks.
In order to meet the market demand, the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) has formulated a series of recommendations for the OTN, among which the Recommendation G.709 is a standard mainly in regard to the structure and mapping of OTN frames. The standard frame structure defined in the Recommendation G.709 is as shown in FIG. 1. An OTN frame is a 4080*4 modular structure, and includes: a Frame Alignment Signal (FAS), configured to provide a frame synchronization and alignment function; Optical Channel Transport Unit (OTU)-k (OTUk) Overhead (OH), configured to provide an OTU-level network management function; Optical Channel Data Unit-k (ODUk) OH, configured to provide a maintenance and operation function; Optical Channel Payload Unit-k (OPUk) OH, configured to provide a service adaptation function; an OPUk payload area, also referred to as a payload area of the OTN frame, mainly configured to provide a service bearer function; and an FEC area, configured to provide an error detection and correction function.
In a scenario of transporting high rate service, if a client signal is mapped to the OPUk payload through an existing mapping method, the mapping process is rather complicated. For example, when the client signal is mapped to OPU0 through an existing mapping method based on the Generic Mapping Procedure (GMP), if the bit width for processing is 16*8 bits, each clock cycle requires 16 times of sigma-delta calculation in order to complete the mapping of the client signal in the clock cycle, so that the mapping process is complicated.